Fundus color and angiographic images were obtained using 2 digital capturesystems. Before April 2000, fundus photography and angiography were performedusing the Ophthalmic Imaging System (Ophthalmic Imaging Systems Inc, Sacramento,Calif) equipped with a Topcon SL7F fundus camera (Topcon, Surrey, Great Britain)and a black-and-white charge-coupled device camera (Sony Corp, New York, NY),with each image occupying 512 × 512 × 16-bit pixels, where 1 pixellength was equivalent to 17.6 µm. Accompanying color photographs werecaptured on 35-mm film. From April 2000 onward, images were captured on theTopcon retinal camera (model 50IX; Topcon) with IMAGEnet 2.11 software (IMAGEnet,Melbourne, Victoria). The high analogue definition charge-coupled device camera(HAD3CCD; Sony Corp), with 800 × 600-pixel resolution per chip for eachof the 3 colors, and a KodakMegaplus camera (model 1.4i/10; Redlake, Vianen,the Netherlands) were used for the capture of color and angiographic images,respectively. Images from angiograms captured on the Ophthalmic Imaging Systemwere imported into an Image Tools program (a free software program for imageanalysis) before grading. Images captured on the Topcon digital system wereanalyzed using IMAGEnet software.